Described below is a method for emission of alarm messages to subscriber terminals in a radio communications system, in particular for emission to mobile subscriber terminals in a mobile radio system. Also described are a subscriber terminal, a radio network controller and a radio communications system for carrying out the method.
The occurrence of catastrophes, caused either naturally or by people, still represents a major requirement for the public authorities in particular with regard to the need to provide a rapid and comprehensive alarm system for the population affected. The traditional use of alarm sirens which are installed covering areas in at least some countries in this case in particular has the disadvantage that no specific information can be transmitted, not least because it cannot be assumed that the population wish to distinguish between different alarms. Further known methods for alarming the population include television and radio broadcast transmissions, although these have the disadvantage that they can be received only by terminals that are being used.
In addition to this use of public facilities, methods have been developed which provide alarms by cable-based or mobile communications systems. In particular, mobile radio systems appear to be suitable for applications such as these in this case, since, in particular in countries with a high penetration rate, a large proportion of the population can be accessed irrespective of their current location. Methods based on communications systems have the disadvantage, however, that the dedicated dialling of a large number of telephones takes a long time. This is particularly true when using the so-called short message service (SMS), as is implemented inter alia in the known GSM mobile radio system. Furthermore, the transmission of short messages has the negative effect that the mobile radio system, which is generally already heavily loaded, is additionally loaded, thus making it possible for further delays to occur in the transmission of short messages.
Methods are therefore being introduced to speed up the transmission of short messages, making use of the so-called “cell broadcasting” functionality of the GSM mobile radio system. In this context, reference is made by way of example to the internet page that was available at www.cell-alert.co.uk/emergency_management.htm, which also supported the above statements. Despite the advantages achieved in this way, it is, however, disadvantageously necessary in terms of the alarm speed and the load on the mobile radio system for each of the subscribers to have enabled the function of reception of cell broadcast messages on their terminals, since the terminal will otherwise not receive such messages, or display them.